Contact detection algorithms for DEM simulations of tablet-shaped particles

The shape of standard round tablet was represented by using the intersection of three spherical surfaces. Using this model, the contact criteria for tablet-flat surface and tablet-tablet contact were developed and were applied for tablet-tablet contact using a DEM simulation implemented in Matlab™ code. In addition, a high-speed digital imaging system was used to capture the images of one tablet hitting another fixed tablet anchored to a flat surface. Comparison of angular velocity showed good agreement between simulation and experimental results. The simulations were compared with alternative multi-sphere representations for the shape of the tablet and the results showed that the simulation times for 66- and 178-sphere representations were much larger than that for the tablet simulations. In addition, the simulation results for all the multi-sphere representations were significantly different from those of the tablet simulation.     

Remote sensing of emissions from in-use small engine marine vessels

This paper reports the first use of a remote sensing device to measure emissions from in-use marine vessels. Emissions from 307 small marine vessels were measured as they passed through the Hiram M. Chittenden locks near Seattle, WA. Of these vessels, 89 were matched to state registration information to allow for further analysis of emissions vs model year, fuel type, and engine type. Emission factors are reported for CO, HC, and NOx in grams of pollutant per kilogram of fuel. The measured emission factors generally agreed with those derived from laboratory studies. HC emissions are disproportionately skewed across the fleet where 40% of the emissions come from just 10% of the fleet. These are most likely due to the remaining two-stroke engines in the fleet. CO and HC emissions show no improvement with newer vessels.     

Augmentation of LTP induced by primed-bursts tetanic stimulation in hippocampal CA1 area of morphine dependent rats

The authors have previously shown that the type 1 insulin-like growth factor receptor (IGF-1R) is decreased in the transformation from benign to malignant human prostate epithelial cells in vivo. Further, in a well-described human SV40-T immortalized human epithelial cell system beginning with the immortalized, but rarely tumorigenic P69SV40-T cell line, to the highly tumorigenic and metastatic M12 subline, there is a similar decrease in IGF-1R number from 2.0 x 10(4) receptors per cell to 1.1 x 10(3) receptors per cell. When the IGF-1R was reexpressed in the M12 subline using a retroviral expression vector, M12-LISN, to a receptor number similar to that of the P69SV40-T parental cell line, the authors demonstrated a marked decrease in colony formation in soft agar in the M12-LISN cells vs the M12 control cells (p < or = 0.01), and a decrease in vivo tumor growth and metastases when injected either subcutaneously or an intraprostatic location (p < or = 0.01). This decrease in tumor volume was not because of a decrease in proliferative capacity, but was associated with an increase in apoptosis in baseline cultures and in response to the apoptotic-inducing agents 6-hydroxyurea, retinoic acid, and transforming growth factor beta 1.     

Fetoplacental vascular tone during fetal circuit acidosis and acidosis with hypoxia in the ex vivo perfused human placental cotyledon

OBJECTIVES: Our purpose was to determine the effects of acidosis and acidosis-hypoxia on fetoplacental perfusion pressure and its response to angiotensin II. STUDY DESIGN: Perfused cotyledons from 14 placentas were studied with either an acidotic fetal circuit perfusate (n = 7) or an acidotic-hypoxic fetal circuit perfusate (n = 7). Each cotyledon's fetal vasculature was initially perfused under standard conditions and bolus injected with 1 x 10(-10) moles of angiotensin II. Fetoplacental perfusate was then replaced with either an acidotic medium (pH 6.90 to 7.00 and Po2 516 to 613 mm Hg) or an acidotic-hypoxic medium (pH 6.90 to 7.00 and Po2 20 to 25 mm Hg) followed by an angiotensin II injection. The vasculature was subsequently recovered with standard perfusate and again injected with angiotensin II. Perfusion pressures within each group were compared by one-way analysis of variance, and results were expressed as mean pressure +/- SEM. RESULTS: Resting fetoplacental perfusion pressure did not change when the fetal circuit perfusate was made acidotic (28 +/- 1 mm Hg vs 25 +/- 2 mm Hg) or acidotic-hypoxic (26 +/- 2 mm Hg vs 25 +/- 2 mm Hg). The maximal fetoplacental perfusion pressure achieved in response to angiotensin II did not differ with an acidotic perfusate (41 +/- 2 mm Hg vs 38 +/- 1 mm Hg) or with an acidotic-hypoxic perfusate (39 +/- 2 mm Hg vs 36 +/- 2 mm Hg). CONCLUSIONS: In the perfused placental cotyledon fetoplacental perfusion pressure and pressor response to angiotensin II are not affected by fetal circuit acidosis or acidosis-hypoxia. This suggests that neither fetal acidosis nor fetal acidosis combined with hypoxia has a direct effect on fetoplacental vascular tone.     

Children's use of sample size and diversity information within basic-level categories

Category-based induction involves making decisions about some member(s) of a category based on information concerning other category members. Recent studies indicate that although adults make use of information concerning sample size (larger samples are a stronger basis of inference than smaller samples) and sample diversity (more diverse samples are better than more homogeneous samples) when making category-based inductive judgments, children do not do so until age 8 or 9 and even then to only a limited degree. This research however, was conducted at the superordinate level of categorization, and it is unclear if general difficulty with this category level may have masked children's ability to use size and diversity, or if these results represent a more entrenched conceptual difficulty in using this information. We therefore conducted three studies that investigate both 8- and 9-year-olds' and adults' ability to use sample size and diversity within basic level categories. Our results indicate that children's difficulty with this information is independent of category level, and may be based on preferences for other strategies concerning category membership and perceptual similarity.     

Heat transfer from flames in a rotary kiln

Heat flow in the flame zone of a direct-fired rotary kiln has been modeled mathematically. The flame has been assumed to be cylindrical in shape, backmixed radially, and moving axially in plug flow. The length of the flame and the rate of entrainment of secondary air have been characterized by empirical equations reported in the literature. It has been shown that the axial component of radiation can be reasonably neglected since it is relatively small compared to the radial component. The resulting one-dimensional model is capable of predicting the axial temperature profiles of the flame and wall and the axial profiles of heat flux to the solids bed and refractory wall. The model has been employed to study the influence on heat flow to the bed of the following variables: fuel type (fuel oil, natural gas, producer gas), firing rate, temperature of secondary air, pct primary air, and oxygen enrichment. Of the three fuels, combustion of fuel oil gives the longest flame and the greatest heat input to the solids in the flame zone. Raising the secondary-air temperature increases the flame length significantly but has a small effect on the maximum flame temperature and heat flux to the solids. Increasing percent primary air decreases the flame length and increases the peak values of flame temperature and solids heat flux but reduces the quantity of heat received by the solids in the flame zone. Oxygen enrichment results in a shorter flame, higher maximum flame temperature, and increase in the heat transferred to the solids in the flame zone. Formerly Graduate Student, University of British Columbia     

Anophthalmic socket and orbital implants. Role of CT and MR imaging

The role of CT and MR imaging examination of orbital implants and the anophthalmic socket is expanding constantly. As the imaging techniques gain refinement and resolution, the list of potential clinical application grows. Frequent clinical-radiologic queries regarding the anophthalmic socket include neuro-radiologic findings with congenital anophthalmia or bilateral microphthalmia, the vascularization or position of an orbital implant following enucleation, or orbital recurrence of tumor following enucleation. Common clinical-radiologic questions regarding orbital implants relate to the associated findings of trauma, infection, bleeding, or recurrence of tumor in relationship to the existing orbital implant.     

High-dose etoposide enables the collection of peripheral blood stem cells in patients who failed cyclophosphamide-induced mobilization

A case of an intracranial cavernous angioma, which presented with headaches and seizures in a pregnant patient, is described. Diagnosis was established with magnetic resonance imaging. A computer-assisted literature search uncovered no previously reported case of intracranial cavernous angioma initially presenting during pregnancy.     

Radicular compression by brucellar epidural abscess

Fifteen children with protein-energy malnutrition and eight healthy children between the ages of 6 months and 60 months were studied for blood glucose and serum insulin levels in the fasting state and 120 minutes following oral glucose load. The measurements were repeated after normalization of the body weight following 6 weeks of nutritional rehabilitation. The fasting blood glucose increased significantly in the post-treatment period and became comparable to the control value. The abnormal blood glucose response to oral glucose load also normalized. The serum insulin level rose significantly (p < 0.001) in the post-treatment period but failed to normalize. The response to oral glucose load was similar. The observed lower insulin response, despite normoglycemia, after 6 weeks of nutritional rehabilitation indicates persistence of hormonal imbalance which may need a longer duration of rehabilitation for full recovery.     

Interactive panoramic map-like views for 3D mountain navigation

In 3D terrain navigation applications, the views based on general perspective projection often find features of interest (FOIs) being occluded. As an alternative, panorama-like views preserve the similarity between 3D scenes before and after the deformations while ensuring the visibility of interested features. In this paper, an automatic method for generating panoramic map-like views is proposed in mountainous areas. The created panorama-like views by moving up the view position as well as the terrain deformation can successfully avoid occlusions of the FOIs. The final views also ensure the resemblance in appearance for the FOIs and landscapes, and thus satisfy the demand for interactive occlusion-free navigation in 3D complex terrain environments.